Adamantane is a stable, highly symmetrical compound in which four cyclohexane rings are condensed to form a cage-like structure. It is known that adamantane derivatives, which show peculiar functions, are useful as raw materials for medical materials and highly functional industrial materials. Further, because adamantane has specific optical characteristics and heat resistance, an attempt has been made to use it as, for example, an optical disc substrate, an optical fiber or a lens (see, for example, Patent Documents 1 and 2). An other attempt has also been made to use an adamantane ester as a raw material for a resin photoresist by utilizing its sensitivity to an acid, dry etching resistance and transparency to UV rays (see, for example, Patent Document 3).
In recent years, studies have been made to attain high fineness, wide sight angle and high image quality of flat panel displays using liquid crystals or organic electroluminescence (EL) elements, to use high frequency in electronic circuits and to achieve high performance and improvement of optical and electronic parts in optical circuits and optical communication.
In this circumstance, an attempt is being made to improve fluorine-containing material which is used in a low refraction index layer for a reflection preventing film of displays and in optical fibers and optical waveguides for optical communication. Since, in general, a fluorine atom-containing compound has a low refractive index, studies are being made to use a fluorine-containing resin material having a low refractive index for a reflection preventing film for liquid crystals and organic EL displays, a lens such as a Fresnel lens, a lenticular lens or a microlens array, an optical fiber and an optical waveguide.
For example, in a reflection preventing film in which low refractive index and high refractive index layers are alternately laminated for the prevention of reflection, a straight chain polymer of a fluorine-containing acrylate is used as a resin of the low refractive index layer (see, for example, Patent Documents 4 and 5). Because the resin is straight-chained, a sufficiently high surface hardness cannot be obtained and a problem is caused with respect to the mar resistance. In the field of optical fibers and optical waveguides, it is well known that C—H bonds in an organic compound cause an optical loss. To cope with this problem, a material in which such C—H bonds are substituted by C—F bonds is used. For example, the use of a straight chain fluorine-containing acrylate resin is proposed (see, for example, Patent Document 6). The heat resistance of such an acrylate resin, however, is insufficient to withstand reflow soldering and heat generation at the time of communication.    Patent Document 1: Japanese Unexamined Patent Application Publication No. H06-305044    Patent Document 2: Japanese Unexamined Patent Application Publication No. H09-302077    Patent Document 3: Japanese Unexamined Patent Application Publication No. H04-39665    Patent Document 4: Japanese Unexamined Patent Application Publication No. H11-2702    Patent Document 5: Japanese Unexamined Patent Application Publication No. 2001-48943    Patent Document 6: Japanese Unexamined Patent Application Publication No. 2002-182046